Bring a large pot of generously salted water to a boil over high heat. Meanwhile, in an 11- to 12-inch skillet, heat the oil over medium-high heat until very hot.

Add the tomatoes (be careful because the oil and juice can spatter) and cook until they begin to collapse and their juices run and start to thicken, 6 to 10 min. (If you have big, stubborn tomatoes, you may need to crush them a bit with a spatula or pierce them with a knife.) Add the garlic and cook for 30 seconds.

Remove the pan from the heat and stir in the tuna, pepperoncini, capers, lemon juice, butter, and lemon zest.

Season the sauce to taste with salt and keep it warm while you cook the pasta.

Cook the pasta in the boiling water according to package directions. Drain well, arrange in individual pasta bowls, and top with the sauce and the parsley.